package com.webserver.http;

import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.Element;
import org.dom4j.io.SAXReader;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.net.Socket;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;

/**
 * 响应对象
 * 该类的每一个实例用于表示服务端给客户端发送的一个HTTP响应内容。每个响应由三部分构成:
 * 状态行，响应头，响应正文
 */
public class HttpResponse {
    //状态行相关信息
    private int statusCode = 200;//默认值200
    private String statusReason = "OK";//默认值OK

    //响应头相关信息
    private Map<String, String> headers = new HashMap<>();



    //响应正文相关信息
    private File entity;//响应正文对应的实体文件

    private Socket socket;

    public HttpResponse(Socket socket) {
        this.socket = socket;
    }

    /**
     * 将当前响应对象内容以标准的响应格式发送给客户端
     */
    public void flush() throws IOException {
        //1发送状态行
        sendStatusLine();
        //2发送响应头
        sendHeaders();
        //3发送响应正文
        sendContent();
    }

    private void sendStatusLine() throws IOException {
        String line = "HTTP/1.1" + " " + statusCode + " " + statusReason;
        println(line);
    }

    private void sendHeaders() throws IOException {
        Set<Map.Entry<String, String>> entrySet = headers.entrySet();
        for (Map.Entry<String, String> e : entrySet) {
            String name = e.getKey();//响应头的名字
            String value = e.getValue();//响应头对应的值
            String line = name + ": " + value;
            println(line);
        }

        //单独发送CRLF表示响应头发送完毕
        println("");
    }

    private void sendContent() throws IOException {
        if (entity != null) {
            try (
                    //利用异常处理机制的自动关闭特性，确保文件流使用后被关闭
                    FileInputStream fis = new FileInputStream(entity);
            ) {
                OutputStream out = socket.getOutputStream();
                byte[] data = new byte[1024 * 10];//10kb
                int len;//每次实际读取到的字节数量
                while ((len = fis.read(data)) != -1) {
                    out.write(data, 0, len);
                }
            }//这里不写catch是因为异常抛出给流程控制来处理。
        }
    }

    private void println(String line) throws IOException {
        OutputStream out = socket.getOutputStream();
        byte[] data = line.getBytes("ISO8859-1");
        out.write(data);
        out.write(13);//发送一个回车符
        out.write(10);//发送一个换行符
    }

    public int getStatusCode() {
        return statusCode;
    }

    public void setStatusCode(int statusCode) {
        this.statusCode = statusCode;
    }

    public String getStatusReason() {
        return statusReason;
    }

    public void setStatusReason(String statusReason) {
        this.statusReason = statusReason;
    }

    public File getEntity() {
        return entity;
    }

    /**
     *  添加响应正文对应的实体文件
     *   添加该文件的同时会根据试题文件自动添加两个说明正文的响应头：Content-Type和Content-Length
     * @param entity
     */
    public void setEntity(File entity) {
        this.entity = entity;

        //设置响应头
        // 1根据entity获取该正文文件的文件名
//        String[] fileName = entity.getName().split("\\.");
        String fileName = entity.getName();

        // 2根据文件名获取到资源后缀名
        String ext = fileName.substring(fileName.lastIndexOf(".") + 1);

        // 3根据资源后缀名设置Content-Type的值
//        Map<String, String> mimeMapping = new HashMap<>();
//        mimeMapping.put("html", "text/html");
//        mimeMapping.put("css", "text/css");
//        mimeMapping.put("js", "application/javascript");
//        mimeMapping.put("png", "image/png");
//        mimeMapping.put("gif", "image/gif");
//        mimeMapping.put("jpg", "jpeg");
//
//        String type = mimeMapping.get(ext);

        String type = HttpContext.getMimeType(ext);
        System.out.println(ext + "的mime-type：" + type);

        //3根据资源后缀名设置Content-Type的值
        putHeaders("Content-Type", type);
        putHeaders("Content-Length", entity.length() + "");



    }

    /**
     *  添加一个要发送的响应头
     * @param name
     * @param value
     */
    public void putHeaders(String name, String value) {
        this.headers.put(name, value);
    }
}






